SDK15.3 S132 disconnect from oppo when send data

[taol]

This is my problem description, hope someone can help me.
1. The watch product shipped in mass production is found to be disconnected when using the mobile phone OPPO-k7x to send a file. No problems have been found on other phones for the time being.
2. The watch software uses SDK15.3, S132, and there are logs after connecting with the mobile phone:
nrf_ble_gatt: max_rx_octets: 251
nrf_ble_gatt: max_tx_octets: 251
nrf_ble_gatt: max_rx_time: 328 (this parameter is 2120 when other mobile phones are connected)
nrf_ble_gatt: max_tx_time: 2120
3. When the same software code and sdk_config use S112 protocol stack, it is no problem to connect OPPO-k7x.
4. The influence of hardware signals and ble_gap_conn_params has been excluded.
5. When the watch is connected to OPPO-k7x, the short data packet communication is normal, and it is disconnected when only sending large data. The reason is 0x08[BLE_HCI_CONNECTION_TIMEOUT]. The Wireshark log is:

[Simonr]

Hi

If another similar OPPO phone works as intended, please try delete bonding information on both the nRF device and OPPO phone to make sure that one of them don't think they're already bonded and therefore skips vital parts of the connection process while the other device does not. This will likely cause a timeout like you're seeing in a specific device.

If not, please upload the sniffer log as a .btt file so I can review it. Are the two OPPO phones the same model and do they run the same Android version?

Best regards,

Simon

[taol]

Thanks again.

The device is not bound to OPPO. Through the link I forwarded and compared with the nrf_ble_gatt.c of S112 and S132, I blocked the data_length_update call under on_connected_evt when connecting. This problem has been solved, because the device does not need to be related to the center. I guess this will not cause other problems. Thanks for your help.